Figure 3

The HER2 gene-protein assay yields appropriate staining of HER2 protein, the HER2 gene, and CEN17 in FFPE clinical breast cancer tissues. Tissues with HER2 IHC scores of 3+ (A–C), 2+ (D–F), 1+ (G–I), and 0 (J–L) were subjected to HER2 IHC assay (A, D, G, J), HER2 & CEN17 BISH assay (B, E, H, K), or the HER2 gene-protein assay (C, F, I, L) using tissue microarray slides. HER2 IHC assay yielded the expected HER2 protein staining (A, D, G, J) and the separate HER2 & CEN17 BISH assay yielded the expected staining of the HER2 gene (black dots) and CEN17 (red dots) (B, E, H, K). The combined assay yielded both the appropriate HER2 protein staining and the appropriate HER2 gene and CEN17 staining (C, F, I, L). [All images 60×.].